Architectural specification : Architectural Specification: Base : Configuration, specialization, and constraints : Specialization : Specialization module coding requirements : XSD schema specialization module coding requirements
   
XSD schema specialization module coding requirements
 
General element type declaration coding requirements
Structural specialization coding requirements
Attribute domain coding requirements
To be extensible and backward compatible, DITA requires that an XSD implementation of structural and domain specialization modules conform to well-defined implementation (coding) requirements.
These design patterns implement the specialization architecture with the capabilities and within the limitations of the XML Schema grammar. They are the coding requirements for structural specializations, domain specializations, and attribute domain specializations.